The silver LA4 Line Amplifier from Benchmark is a line-level preamplifier designed to sit between a reference-quality D/A converter and a reference-quality power amplifier. It offers relay gain control, relay input selection, and relay muting, and incorporates premium gold-contact relays. The gain control has 256 steps in 0.5 dB increments. Relay closures are precisely timed to deliver smooth volume changes. The LA4 incorporates a total of 40 precision relays and two independent 256-step attenuators, one for the left channel and one for the right channel.

The rear-panel I/O includes two balanced stereo XLR inputs, two unbalanced stereo RCA inputs, XLR and RCA stereo outputs, and a mono XLR output. Volume adjustments are executed via the 256-step balanced relay gain control, which uses increments of 0.5 dB. The integrated touchscreen allows convenient access to common functions such as input selection, dim, mute, and more.

High Voltage, Current, and Power    256-Step Balanced Relay Gain Control    100% Analog Signal Path    Balanced and Unbalanced Line I/O    Touchscreen Control    Designed, Assembled, Tested in the USA

The LA4 is 100% analog. It is designed to be driven from external D/A converters and external line-level analog sources, and to drive any professional or hi-fi power amplifier.

At any volume setting, the relay-controlled gain stage provides an optimized attenuator to match the upstream analog source to the downstream power amplifier. This optimization of the gain staging delivers the best possible system SNR for each volume setting. The LA4 matches high-output D/A converters to low-input power amplifiers and vice versa. It also provides an optimized interface to and from balanced and unbalanced devices. In addition, it matches high-level professional balanced interfaces to low-level hi-fi balanced interfaces (in either direction).

The bandwidth of the LA4 extends from 0.01 Hz to over 500 kHz. This means that the LA4 delivers very precise amplitude and phase accuracy over the entire audio bandwidth. Wave shapes are accurately reproduced, and the entire spectrum is delivered with precise timing. The LA4 is designed to deliver musical overtones with lifelike accuracy so the sonic character of musical instruments is rendered truthfully.

The LA4 features two balanced stereo inputs and two unbalanced stereo inputs. The line amplifier provides one balanced stereo output, one balanced mono sum, and one unbalanced stereo output.

The LA4 can be operated using a separately available remote control. The LA4 is designed to work with the separately available DAC2 and DAC3 converters but may be driven from any high-end D/A converter. When paired with a Benchmark DAC, a single remote control will operate both units.

Two bidirectional 12V trigger ports can be used to link the LA4 with external D/A converters and power amplifiers. The trigger signal controls the power-up and power-down sequencing of the entire audio system. The trigger ports are compatible with most industry-standard trigger input or output ports, but can communicate bidirectionally with other Benchmark products.

The touchscreen provides easy access to advanced features such as balance control, input level offsets, input names, screen dimming, remote control, and function locking. Help screens explain the special functions.

The volume control knob features a high-quality optical encoder that is rated for heavy use. An acceleration feature makes it easy to move through the 256 volume steps while maintaining 0.5 dB/step resolution. A press of the control knob will wake, turn on, or brighten the screen if you are using the screen sleep or auto-dim functions.

The LA4 includes an on-screen mute button for the line outputs. The outputs can also be muted with the volume knob or with the remote control.

The LA4 includes an on-screen -20 dB "audio dim" button that instantly reduces the level by 20 dB. This function provides a temporary volume reduction and makes it easy to return to the previous listening level. This control makes it easy to transition between a normal listening level and a background level. The -20 dB "dim" function is also accessible from the remote control.

The inputs may be renamed and unused inputs may be disabled. Input levels can be trimmed to provide input-to-input level matching.

Screen brightness is adjustable and timers can be set to dim or shut off the display. The screen can be locked to prevent access to advanced features.

The case features a milled faceplate and milled sides. Top, bottom, and rear panels are made from thick aluminum and feature a brushed texture.

The LA4 was designed, assembled, and tested in the USA using USA and imported components. Most major components are made in the USA.

Related Questions and Answers

Q: 1. Exactly how does one focus a M style lens on the Leica CL using this adapter? Does the EVF work like a rangefinder when using M style lenses?

A: The CL magnifies the image in the viewfinder to help you focus. Only an M has a split image range finder.

Q: 2. Does the new go pro hero 7 Black work with most drones? Besides the karma and 3DR solo since both are being discontinued. Would this work with a dji phantom 2 or 3 for example? Or any other compatible drones out there?

A: We are not aware of a way to mount the Hero7 Black to products like the Phantom 2 or 3. We do not have any solutions available for that at this time.

Q: 3. Do I need to buy charger or battery?

A: The battery and charging cable comes with the camera. The battery is charged inside the camera itself.

Q: 4. compatible GoPro HERO 7 Black with GoPro Karma Grip?

A: The GoPro Hero 7 Black can be used on the GoPro Karma grip.

Q: 5. We've used Hero Black 3+ for quite a while and find that they still do the job for us in most environments. But we've lately been doing a lot of live concerts where the lighting is not always optimum. The 3+'s are great to setup around the stage but the low light capability is not. Is the Black 7 appreciably better in low light situations?

A: While the Hero7 Black will offer a better low light performance than the Hero 3+ Black, we would still not call it a great camera in low light. It will not be a major improvement.

Q: 6. Does this GoPro Hero7 White have - a wide-angle feature - 720p minimum - 30 FPS - MP4 Format - Linear FOV ?

A: The GoPro Hero 7 White will have a wide angle lens built in. The lowest recording resolution of the is 1080P 30/60 fps in mp4 format and Linear FOV is not available on the Hero 7 White.

Q: 7. Does this camera come with a wrist strap?

A: This does not come with a wrist strap. But does not mean there aren't any. GoPro Hand + Wrist Strap BH #GOHWSTRAP • MFR #AHWBM-002 GTX STUDIO Floating Wristtrap Gopro Yellow2 BH #GTZ520 • MFR #Z-520 Revo Floating Hand Grip for GoPro BH #REACFHG • MFR #AC-FHG

Q: 8. What would happen to a CL, SL2, or SL2-S body if, while using this adapter, a Leica M lens, that is not on the B&H's compatible list of Leica lenses, is installed on to this adapter? For example, a Summilux-M 35mm f1.4 made in Canada?

A: The list provided by B&H is very inclusive but unfortunately, not all-encompassing. All standard, non-collapsible (only a few exist) Leica M-mount lenses should work without issue.

Q: 9. Does the GoPro HERO7 have a 'manual setting' & zoom?

A: There is no optical zoom and there are some manual white balance and exposure settings.

Q: 10. THE "Xuma 2.4A USB Charger with Folding Prongs" (5V / 2.4 A / 12 W) can be used to charge a Go Pro HERO 7 Black?

A: Yes. The Xuma 2.4A USB Charger with Folding Prongs can be used for Charging GoPro cameras including the GoPro Hero 7 Black.